Race, or more correctly, ethnicity, is always a touchy subject at school. "Don't call me Chicana," said one student to another. "That means I'm Mexican, and I'm half Salvadoran."
I raised the question of what chicano/chicana and latina/latino implied. They said that chicana meant Mexican in heritage, but born in the US. Latina meant any country in South America, but not Mexico. It wasn't in South America. They all agreed adamantly that they wanted people not to confuse their heritage.
"It's the same with white people," I commented. "We are Irish, German, Polish, or Italian. Slavs don't want people to think they are Poles. Scottish people don't want to be confused with British or Irish people."
They gaped at me.
"But white people all look alike!"